Lightroom CC: Error 67 - Sign in

Just installed Lightroom CC, Classic and Photoshop still working fine. But Lightroom CC starts with "error 67"."Account Notification""An error has occured while attempting to login to your account."" My email "{ "Error":67 }""Please sign out and sign in again"

But, I have tried this many times... Unistalled... Reinstalled... and Nothing.

When opening the Creative Cloud app, are there any signs that there is an issue with the app? Any errors or loading icons or anything else that might be a concern. I'm trying to narrow down if this is being caused by the CC app or if it's specific to Lightroom CC.

To clarify, this error dialog pops up as soon as you attempt to launch Lightroom CC, correct? Not any other action?

Yes, I am on windows.
I tried that step by step several times and yes, I works, but only once. Next time I start Lightroom CC again there’s again error67..
I removed all adobe-products and cleaned the system with adobes creative cloud cleaner.. after a clean reinstall I have the same issue.
Also tried deactivating and deinstalling AV-Software (avira) witch had also no effect

Only by deleting „opm.db“ I can login once, the second start of lr cc leads again into error67